The future of many countries will be strongly influenced by their capability of meeting increased energy demands. Historically fossil fuels have been the primary source for heating, lighting and operating industrial machinery. Such fuels however, have become expensive, and current estimates indicate that U.S. oil and gas outputs will be negligible by the year 2020. Even now, the prospect of supplying fossil fuels to remote hamlets in underdeveloped countries is economically unfeasible. In such countries, it is essential that self-sufficient energy sources be developed. In most cases, this means direct conversion of solar energy to electricity and heat.
The sun's radient energy however, is more difficult to utilize than fossil fuels because it is of relatively low intensity and, of course, it is not always present. On a clear day, an area of 150 m.sup.2 will receive an average of 126,000 BTU's/hr averaged over 24 hours. The problem however, is in collecting this energy, converting it to a highly available form, storing it for times of no sunlight, and using it when demanded.
There are two basic types of collectors, flat plate and concentrating. Flat plate collectors are usually a rectangular sheet of copper, aluminum or steel, which conducts heat easily. The plate is normally coated with a dark substance, such as black paint, which may absorb as much as 95% of the incident radiation. Much of the energy which is absorbed however, is then emitted as long wave heat radiation -- which reduces the temperature of the plate and consequently the theoretical thermodynamic efficiency -- which is directly dependent upon the difference between the plate and ambient temperatures. Concentrating collectors (such as parabolic mirrors) on the other hand, produce much higher temperature by focusing the sun's rays on a small area where an operating fluid is injected. As a consequence, such devices are capable of higher theoretical efficiencies. In prior art devices however, this theoretical advantage was largely overshadowed by inefficiencies in the energy storage and management system. In addition, such devices are traditionally costly to produce, and normally require complex equipment for tracking the earth's rotation.
What is actually desired is an efficient energy storage, conversion and management system which can be used in conjunction with a parabolic, sun-tracking reflector to provide electricity and heat to isolated population areas.
Accordingly, a primary objective of the present invention is to provide an efficient system for collecting, converting, and storing energy derived from sunlight.
A further object of the present invention is to provide a sun tracking concentrator for focusing solar energy upon a heat exchanger.
Another object of the invention is to provide a heat exchanger for converting a fluid to vapor in a flash process.
Another object of the invention is to provide a system for storing converted solar energy in the form of compressed gas for subsequent use in a gas turbine.
Another object of the invention is to provide a means for storing excess solar energy in the form of heat.
Another object of the invention is to provide a means for utilizing solar energy which is stored in the form of heat to raise the temperature of a gas which has been previously compressed for the purpose of operating a gas turbine.
A further object of the invention is to provide an auxilliary battery system for storing small amounts of energy for specific purposes which do not require heavy discharge rates for extended periods.
Another object of the invention is to provide an energy management system which can automatically adjust, priorities and allocate the tasks of various energy storage and conversion components.
Another object of the invention is to provide a logic system which will automatically locate and track the sun each day.
It is yet another object of the invention to provide a heat exchanger for trapping and collecting the focused rays of a solar concentrator.
Another object of the invention is to provide a flash vaporizor piston engine.
Other objects and advantages of the invention will be obvious from the detailed description of a preferred embodiment given herein below.